This invention relates to vibration isolators for percussive tools; and has for its object to provide a vibration isolator that may be applied as a hand grip to the shank of the work element of such tools.
The invention is especially suited for use with percussive tools known as chipping hammers. In tools of this type a pneumatically powered piston hammer is rapidly reciprocated to repeatedly and forcefully strike a chisel against a work object. The tool is portable, and adapted to be hand held when used. An undesirable problem attending the operation of such tools is created by the considerable vibration imparted to the chisel. This makes it difficult at times for the operator to maintain the working end of the chisel in contact or on target with the work.
Attempts have been made to solve this problem by providing the tool with an elongated slender housing so as to enable the operator to firmly hold the tool in both hands and thereby better steady it relative to the work. Some of the tools are formed with a pistol grip handle to be grasped in one hand while the operator grasps the barrel of the housing in the other to obtain a desired steadying of the work implement on its target.
Despite these attempts, further steadying of the tool against vibration and moving from the work is often required, especially where the target area of the work is small. The operator from experience has found that when necessary he can guide and steady the work implement relative to the work, even where the target area is small, by holding the handle firmly in one hand and grasping the shank of the chisel in the other. While this method of using the tool may provide desirable work results, it transmits considerable undesirable vibratory forces to the hand of the operator. These forces are a source of discomfort, and may be physically damaging to the operator's hand.
Accordingly, the general objective of this invention is to provide a vibration isolating hand grip or sleeve unit for the shank of the work implement or chisel, which may be grasped by the operator to guide and hold the chisel relative to the work without his receiving undesirable vibratory forces in his hand.
Besides the advantage of isolating the vibrations of the chisel from the operator's hand, the sleeve unit has other desirable advantages. It can be readily slipped on or off the shank of a chisel before insertion or after removal of the chisel from the tool. This advantage is of particular value especially in the removing of flashing from castings in foundries and in other operations where a number of chisels, each with a differently formed work tip, are successively used in a work operation. The sleeve may be readily slipped off one chisel, and then slipped onto the next to be used in such operations.